[Chromecast] Set dummy metrics session ID for browser tests

chromecast/base/metrics/cast_metrics_helper.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromecast/base/metrics/cast_metrics_helper.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/metrics/histogram.h"
@@ skipping 73 matching lines @@
 
 // static
 CastMetricsHelper* CastMetricsHelper::GetInstance() {
   DCHECK(g_instance);
   return g_instance;
 }
 
 CastMetricsHelper::CastMetricsHelper(
     scoped_refptr<base::SingleThreadTaskRunner> task_runner)
     : task_runner_(task_runner),
-      session_id_("00000000000000000000000000000000"),
       metrics_sink_(NULL),
       logged_first_audio_(false),
       record_action_callback_(base::Bind(&base::RecordComputedAction)) {
   DCHECK(task_runner_.get());
   DCHECK(!g_instance);
   g_instance = this;
 }
 
 CastMetricsHelper::CastMetricsHelper()
     : metrics_sink_(NULL), logged_first_audio_(false) {
@@ skipping 115 matching lines @@
   MAKE_SURE_THREAD(SetMetricsSink, delegate);
   metrics_sink_ = delegate;
 }
 
 void CastMetricsHelper::SetRecordActionCallback(
       const RecordActionCallback& callback) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   record_action_callback_ = callback;
 }
 
+void CastMetricsHelper::SetDummySessionIdForTesting() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  session_id_ = "00000000000000000000000000000000";

[gfhuang, 2016/02/13 00:34:01]

use GUID format

"00000000-0000-0000-0000-000000000000"

+}
+
 void CastMetricsHelper::RecordSimpleAction(const std::string& action) {
   MAKE_SURE_THREAD(RecordSimpleAction, action);
 
   if (metrics_sink_) {
     metrics_sink_->OnAction(action);
   } else {
     record_action_callback_.Run(action);
   }
 }
 
@@ skipping 27 matching lines @@
     const base::TimeDelta& value) {
   // Follow UMA_HISTOGRAM_MEDIUM_TIMES definition.
   LogTimeHistogramEvent(name, value,
                         base::TimeDelta::FromMilliseconds(10),
                         base::TimeDelta::FromMinutes(3),
                         50);
 }
 
 }  // namespace metrics
 }  // namespace chromecast